Question

Sulphonamides were used to treat microbial infection because they inhibit microbial growth by

• A. Inhibiting wall formation
• B. Competing with PABA required for synthesis of folic acid
• C. Breaking naked DNA of microbes
• D. Inhibiting union of ribosome subunits and preventing protein synthesis

Answer 1

The correct option is B Competing with PABA required for synthesis of folic acid

A folic acid or folate used to synthesize nucleic acid. Sulpha drugs inhibit the enzyme dihydropteroate synthase by attaching on the active site. DHPP and p-aminobenzoic acid (PABA) reacts in the presence enzyme dihydropteroate synthase for the synthesis of folic acid in bacteria. The sulphonamides compete with the PABA required for the synthesis of folic acid.

So, the correct answer is option B.